have you checked out your schedule with the Stray bus schedule to make sure everything works?

I would pick Battambang over K. Thom as there is more to do and see, its a chilled out small city with plenty of riverside bars and some good sights to see nearby. K.Thom has the very interesting Sambor Prei Kuk and the moto ride out there is cool, however you can do similar things in Siem Reap and obviously Angkor Wat is more impressive. For Trekking you are better off in the Cardamoms or Mondulkiri however I think there are some companies doing treks around Siem Reap although not as remote. Google the Mekong Discovery Trail.
I did the Kiwi Experience several years ago as I had just been months in the outback on my own and wanted some social, it worked perfectly, lots of new friends and booze and no responsibility, I enjoyed it but wouldn't do it again, I do understand why you want to go that way. I also see many people on here thinking how much further they can go on the same money.
Hi! so are you saying it's pretty safe to travel single in cambodia (as a girl) and meet friends?
i will only have 3 days to spend there so i don't see the necessity to join any tour. but travel companions would defntly make a difference. :)
angkor wat is a must see. what else would you suggest to put in my 3-day schedule?
thanks a lot!